(display "\n========================================\n")
; make-vect xcor-vect ycor-vect
(define (make-vect x y)
    (cons x y))

(define (xcor-vect v)
    (car v))

(define (ycor-vect v)
    (cdr v))

; add-vect sub-vect scale-vect
(define (add-vect v1 v2)
    (cons (+ (xcor-vect v1) (xcor-vect v2))
          (+ (ycor-vect v1) (ycor-vect v2))))

(define (sub-vect v1 v2)
    (cons (- (xcor-vect v1) (xcor-vect v2))
          (- (ycor-vect v1) (ycor-vect v2))))

(define (scale-vect s v)
    (cons (* s (xcor-vect v))
          (* s (ycor-vect v))))

(define v1 (make-vect 3 4))
(define v2 (make-vect 8 10))
(display v1)
(newline)
(display v2)
(newline)

(display (xcor-vect v1))
(newline)
(display (ycor-vect v2))
(newline)

(display (add-vect v1 v2))
(newline)

(display (sub-vect v2 v1))
(newline)

(display (scale-vect 4 v1))
(display "\n========================================\n")
